Objectives: AAC is a multimodal communication system that augments and provides alternates for individuals with limited verbal skills. It helps people with complex communication needs to communicate effectively with various people, promotes participation in many activities, and further promotes independent life. The purpose of this study was to investigate the response time of the selection of graphic symbols according to the size and number of graphic symbols in 5 and 6 year old typically developing children, to compare the differences, and to find out the correlation between age, vocabulary ability, intelligence, and response time. Methods: The participants were 16 children aged 5 years old, and 17 children aged 6 years. Five AAC boards were developed according to the size and number of graphic symbols. A two-way mixed ANOVA was conducted to find the difference in response time between groups according to AAC board type; and the correlation between age, vocabulary ability, non-verbal intelligence and graphic symbol selection response time was examined. Results: The main effect of the response time for selecting graphic symbols between the 5 and 6 year old groups was significant, and the difference in response time was also significant in the AAC board type according to the size and number of graphic symbols. It was found that age, receptive vocabulary ability, and non-verbal intelligence showed significant correlation according to the size and number of picture symbols. Conclusion: The results of this study show that age, receptive vocabulary ability, and non-verbal intelligence should be considered in selecting the size and number of graphic symbols. The necessity of developing and providing communication boards according to age, vocabulary ability and intelligence of AAC users was discussed.